Index: modules/taxonomy/taxonomy.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/taxonomy/taxonomy.module,v
retrieving revision 1.625
diff -u -p -r1.625 taxonomy.module
--- modules/taxonomy/taxonomy.module	3 Jan 2011 18:03:54 -0000	1.625
+++ modules/taxonomy/taxonomy.module	6 Jan 2011 18:58:42 -0000
@@ -1343,6 +1343,10 @@ function taxonomy_field_formatter_info()
       'label' => t('Plain text'),
       'field types' => array('taxonomy_term_reference'),
     ),
+    'taxonomy_term_reference_rss_category' => array(
+      'label' => t('RSS category'),
+      'field types' => array('taxonomy_term_reference'),
+    ),
   );
 }
 
@@ -1385,6 +1389,18 @@ function taxonomy_field_formatter_view($
         );
       }
       break;
+
+    case 'taxonomy_term_reference_rss_category':
+      foreach ($items as $delta => $item) {
+        $entity->rss_elements[] = array(
+          'key' => 'category',
+          'value' => $item['tid'] != 'autocreate' ? $item['taxonomy_term']->name : $item['name'],
+          'attributes' => array(
+            'domain' => $item['tid'] != 'autocreate' ? url('taxonomy/term/' . $item['tid'], array('absolute' => TRUE)) : '',
+          ),
+        );
+      }
+      break;
   }
 
   return $element;